I'm getting the same:

Here is what I see on Site Mail when I go to send site mail to someone:

mysql error: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '???' at line 1, occured in query: "select username from member where userid = ???".

To:

Please note the "To:" field is blank.  This indicates to me that it is addressed to no one.  I have to manually enter the user name.

Others must be getting the same thing as I am getting nothing but e-mails from people trying to contact me.  No site mail is being used to contact me.

I will have to contact everyone to inform them that I now have their real names and e-mail addresses, and let them know they have to manually enter the username if they want to use Site Mail.

The Site Mail worked until the last 7 days.  If you have any further suggestions or comforting words, I would appreciate them at this point.

“Music is harmony, harmony is perfection, perfection is our dream, and our dream is heaven”
Henri Frederic Amiel